Podiatrists @ Placentia-Linda Foot & Ankle Group

RUNNING INJURIES
METATARSAL STRESS FRACTURE

When foot pain and tenderness occurs under the second metatarsal head in the ball of the foot with walking or running, usually either a metatarsal stress fracture is present, a nerve is being entrapped or a painful callous is present. A callous is usually the cause of the ball of the foot pain if the bone does not hurt with compression from top and bottom but the skin is tender. A nerve problem is present if the pain is between the metatarsal bones in he ball of the foot and the skin and metatarsal heads do not hurt with squeezing the bones. Review the Corn and Callous Page or the Neuroma Page if you think your problem is a painful callus or a neuroma and not a stress fracture.

Many metatarsal stress fractures are associated with a callous formation under the metatarsal head that is being heavily pressured. A metatarsal stress fracture is a condition that occurs from repetitive pressure to the second metatarsal head. The second metatarsal head is the most common of the lesser metatarsal heads to become injured. The second metatarsal will take up most of the weight of the body if the foot is flattening or pronating during gait or standing. The big toe joint is pushed out of the way from the rotation that occurs as the foot pronates during standing and gait and exposes the second metatarsal to excessive pressure. The pain is typically a deep aching type pain that increases with more weight bearing and decreases with rest. One of the examination findings that is helpful is that the foot hurts with squeezing the bones directed from top to bottom. Besides the foot flattening out, the other cause is poor short absorption in the shoes that are used for long walks or athletics. Rarely poor bone density is the cause of stress fractures as well as the first metatarsal becoming too short from a bunion procedure. If the first metatarsal becomes too short, the second metatarsal will take on too much weight and many times a stress fracture will result.

Treatment is first aimed at making the diagnosis and then moving forward with a plan of treatment based on the severity of the stress fracture. Initial intervention for a mild to moderate stress fracture is to off load the second metatarsal head by changing the padding in the shoe or by wearing a padded post-operative shoe. Custom molded foot orthotics are also routinely prescribed along with motion control athletic shoes. Anti-inflammatory medication such as Celebrex will help with the pain but until the pressure is off the foot, the pain will continue. The key is that the body is trying to stop further injury to the bone from further ground pressure. As soon as the bone has no pressure on it from standing and walking, the pain and related disability will diminish quickly. A cast is required for moderate to severe stress fractures and the decision is on a case-by-case basis. Beside x-ray, sometimes a bone scan is performed to make the diagnosis because the stress fracture only is seen on the x-ray after bone healing has occurred. Most of the time, the clinical examination and the history of the patient are the primary factors for making the diagnosis. In certain sports injury situations, a bone growth stimulator is used to speed the time it takes for the body to lay down bone at the stress fracture site. Typically, a stress fracture healed in six weeks before all of the pain is resolved. In using a bone growth stimulator, the stress fracture can be healed in about two to three weeks to allow the athlete to return to full activities. The use of a bone growth stimulator is a decision between you and your doctor and usually the cost prohibits the use of the bone growth stimulator.

If there is a rigid hammertoe deformity, the hammertoe may need to be surgically treated to resolve the callous formation and excessive pressure being placed on the metatarsal head. In some patients, a pad going around the base of the hammertoe helps and is called a buttress pad. However, if there is a hammertoe and the patient developed stress fractures from the hammertoe, usually surgery to straighten out the hammertoe is warranted.
In summary, if you are having pain in the second metatarsal head that is a deep ache, hurts with direct pressure to the bone in the ball of the foot and increases with more weighty bearing, a stress fracture is likely the diagnosis. Mild to moderate stress fractures are treated with padding, foot orthotics, anti-inflammatory medications and if indicated a bone growth stimulator. Moderate to Severe stress fractures require a cast to insure that the pressure is taken off the metatarsal and to insure the bone heals fully. A Podiatrist should be consulted whenever the amount of pain becomes debilitating.